Facial recognition is an important part of any multi-factor identification system. Many existing arts in facial recognition algorithms analyze, in a learning phase, facial features of a reference facial image to obtain a set of reference attributes that positively identify the person subject of the reference facial image. The set of reference attributes is then compared with new facial features of a given facial image. The comparison result is then evaluated to determine percent of confidence in recognizing the given facial image and the reference facial image as being of the same person subject. Such prior art method may be used for user authentication by identifying a live-captured facial image of a user based on the user's pre-recorded reference facial image. However, this user authentication scheme can be defeated by an unauthorized user presenting a photograph of the authorized user to mimic the live-captured facial image.